In the interior of cathode ray tubes, for instance television tubes, picture tubes of data and radar display apparatus or the like, billions of gas atoms are still present in spite of the rather high vacuum. At acceleration voltages of 10 kV and greater, these remaining gas particles are ionized by very fast electrons flowing from the cathode to the screen (anode). This produces positively loaded atoms (cations), which flow towards the cathode and exit at the tube bulb. This concentrated cathode beam extends as far as about 50 m and penetrates thick walls. At the front side of a display tube, anions (negatively charged atoms) are discharged. The discharge is not concentrated, but diffuse. At an acceleration voltage of 25 kV the presence of said anions can still be found at a distance of about 10 m from the front of the display tube. Proof of this can be provided by leaf electrometers or filament electrometers or by measuring the bio-currents on the body of the human being watching the screen. In the past, experiments and investigations have been made to prevent the occurrence of unknown rays of radiation from television sets, which discharge onto the body of the viewer. However, they have not produced any useful results or insight so far.
The ion beams or alternatively anions and X-rays present on the front side of cathode ray tubes have a harmful effect on the human body. Measurements have shown that the human body requires more than 24 hours to build up the charge of the body which has been lost as a result of anion radiation of 10 minutes duration sufficiently to allow the biopotentials to be measured again. This radiation causes transient radiation damage in the human or animal body. Practice shows that radiation damage occurs in television and radar technicians, the origin of which had not previously been explained.